Helical groove cutting machine



` Dec. 2o, 1960 Filed 00T.. l, 1959 J. G. SCHOTTHOEFER HELICAL GROOVE CUTTING MACHINE 5 Sheets-Shes?I l WiL/@wieg Dec. 20, 1960 J. G. scHoTTHOEFl-:R 2,965,009

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BY @6L United States Patent O HELICAL GROOVE CUTTING MACHINE Joseph G. Schotthoefer, 20030 Wexford, Detroit 34, Mich.

Filed Oct. 1, 1959, Ser. No. 843,848

Claims. (Cl. 90 28.1)

The present invention relates to a helical groove cutting machine.

A primary object of the invention is to provide a machine of relatively simple and dependable construction whereby helical grooves are capable of being formed in a work piece with accuracy and with the expenditure of minimum time and eiort.

A further object of the invention is to provide a helical groove cutting machine which includes a tool-carrying ram, together with means for -axially reciprocating the ram through a predetermined axial range and therewith oscillating the ram about its axis.

'A still further object of the invention is to provide a helical groove-cutting machine as immediately above having provision for selectively varying the angular range of oscillation of the tool-carrying ram.

A still further object of the invention is the provision of adjustable means for disposition of the ram at diiferent angles relative to a normal vertical position thereof.

Other objects and advantages of the invention will become apparent in the course of the following detailed description, taken in connection with the accompanying drawings, wherein- Figure 1 is an elevational view of the improved machine in accordance with a preferred structural embodiment thereof.

Figure 2 is a view partly in elevation and partly in vertical section as observed in the planes of the broken line 2 2 on Figure 1.

Figure 3 is an elevational view on an enlarged scale of an adjustable lead converting mechanism embodied in the machine.

Figure 4 is a vertical sectional view yas observed in the plane of line 4 4 on Figure 3.

Figure 5 is a vertical sectional view as observed in the plane of line 5 5 on Figure 3.

Figure 6 is a vertical sectional view as observed in the plane of line 6 6 on Figure 3.

Figure 7 is a horizontal sectional view as observed in the plane of line 7 7 on Figure 3.

Figure 8 is a vertical sectional view of a portion of the driving mechanism.

Figure 9 is a side elevational view of a clamping device embodied in the machine.

Figure 10 is an end elevational view of the clamping device.

Referring now in detail to the drawings, the improved machine, in accordance with a preferred structural embodiment thereof, comprises a frame including a base 10 having suitable supporting feet 11 and a pair of laterally opposed hub projections 12 on the upper face thereof.

As will be seen from a comparison of Figures 1 and 2, the base 10 is of elongated rectangular form and the hub projections 12 are disposed adjacent the opposite ends thereof and intermediate the opposite side edges thereof.

A pair of vertically disposed tubular columns 13 have their lower ends disposed within and secured to the hub projections 12, as is clearly indicated in Figures l and 2.

A pair of L-brackets are disposed immediately above fice the base 10 adjacent opposite ends thereof and laterally outwardly of the hub projections 12. The L-brackets have corresponding arms 14 thereof disposed vertically and secured to the base 10, and the other arms 15 of the brackets are disposed horizontally and project toward each other in vertically spaced relation to the base 10.

A horizontal shaft 16 is disposed immediately above the base 10 and Whose opposite ends are rotatably journalled in the vertically disposed arms 14 of the L-brackets, and the shaft 16 is provided with a miter gear 17 disposed adjacent the inner wall of each of the respective L-brackets.

One end of the shaft 16 is provided with a hand operable crank 18 for imparting rotation to the shaft 16.

A T-bracket 19 is vertically adjustably supported on each of the columns 13 at positions vertically above the base 10.

Each of the brackets 19 is provided with an internally threaded projection 20 extending laterally outwardly thereof, and a threaded rod 21 is adjustably positioned within each of the threaded projections 20.

A miter gear 22 is secured to the lower end of each of the rods 21 in meshing engagement with a respective miter gear 17.

A bracket 23 is rigidly connected with each of the columns 13 -adjacent .the lower end thereof, and which brackets are rigidly connected by a member 24 to which a work support 25 is adjustably clamped as by bolts 25a.

A universal cross rail is disposed between the brackets 19, and which includes opposed axially aligned cylindrical members 26 and a ramsupporting tubular guide member 27 which is rotatably adjustable relative to the point of intersection of the axes of the cross rail and the ram-supporting member 27, as is indicated at 27a, whereby the axis of the ram-supporting member 27 may be disposed at variable degrees relative to the vertical.

A generally rectangular outer box frame 28 is supported on the upper end of member 27 and rigidly secured thereto by bolts 28a, as is indicated in Figure l.

A ram 29 extends vertically through the frame 28 and is journalled for reciprocatory and rotary movement relative thereto.

A pair of vertically spaced gears 30 are disposed within the frame 28 in freely surrounding relation to the ram 29, and the gears are each provided with a hub 30a which is engaged with the lixed frame 28 `and secured thereto as by bolts 31.

A rectangular cradle frame 32 is disposed within the fixed frame 28 and through which the ram 29 extends with provision for rotation of the frame 32 about the axis thereof.

A rack frame 33 is freely disposed within the cradle frame 32, and which comprises upper and lower toothed rack bars 34 and 35 which are disposed tangentially to the gears 30 with some of the teeth thereof always engaged with the teeth of the gears 30.

Supported within the frame 32 and journalled on Vertical axes are four rollers 36, an upper pair and a lower pair. The rollers 36 are supported by bolts 36al whose axes are equally spaced from an adjacent side wall of the cradle frame 32, and the bolts are supported by the upper and lower walls of the cradle frame, as is clearly shown in Figure 3.

Disposed between the upper and lower pairs of rollers Y36 are a pair of horizontal axis rollers 37. The upper pair of vertical axis rollers 36 bear on the rack frame 33 adjacent its upper end.

The rack frame 33 is provided with a right angular shoulder 38 whose upper and lower walls are engaged by the horizontal axis rollers 37, whereby the rack frame 33 is constantly maintained in operative engagement with the xed gea-rs 30.

Disposed within the rack frame 33 is a calibrated cam track adjusting disk 39, which is rotatably adjustable about `axis 40, and rigid with which is an angular cam track 41. Also disposed Within frame 32 is a vertically disposed track 42.

The adjusting disk 39 and cam track 41 are supported immediately within the side Wall of the rack 4frame 33, while the track 42 is supported within one side wall of the rectangular cradle frame 32.

A clamping device 50 or cross'head, shown more in detail in Figures 9 and 10, is secured to the ram 29 as by means of a screw 51, and on opposite ends of which are rotatably supported pairs of rollers 52 and 53 which engage tracks 41 and 42, respectively.

The driving mechanism comprises a bracket 60 supported on the top of frame 28. A driven shaft 61 is rotatably supported in the bracket 60 and is provided with a disk 62 having an eccentric pin 63 which is rotatably supported in a yoke 64 in which is provided a bearing assembly 65 for the ram 29.

As is indicated in Figure 8, the bearing assembly 65 comprises ya cylindrical member 66 which is rotatably supported within the yoke as at 67 for provision of lateral adjustment of the ram 29, and since the ram is rotatable as Well as reciprocal, ball bearings 68 are provided within the cylindrical member 66.

An offset boring head 69 is supported on the lower end of the ram 29, as indicated in Figure 2, as is also a tool bar 70 and a tool bit 71. l

The operation of the machine is as follows:

A work piece is supported on the Work support 25 for operation thereon by the tool bit 71 which is supported by the boring head 69 which in turn is carried by the lower end of the ram 29. Power is applied to the shaft 61 and through the eccentric pin 63, yoke 64, and the bearing assembly 65, the ram 29 is reciprocatedthrough an axial range equal to throw of the pin 63.

Concurrent with the reciprocal movement of the ram, same is oscillated about its axis in the following manner.

The clamping device 50 or crosshead, being rigidly supported by the ram 29, will reciprocate therewith and in which action the cooperating `angular cam track 41 and rollers 52 will impart limited rotation of the crosshead 50 about the axis of ram 29 with a corresponding angular rotation of the ram about its axis, since the crosshead 50 is rigid with the ram 29. In such action, the cooperating vertical track 42 and the rollers 53 Will cause rotation of the cradle frame 32 about said axis and through the same angular range.

The angular range of movement of the ram about its axis is dependent upon the angularity of the cam track 41, which is adjustable by means of the calibrated adjusting disk 39 and track 41 may be in either dotted line position in Figure 4 or in any intermediate positions.

In the rotation of the cradle frame` 32 about the axis of ram 29 the rollers 36 and 37 are' carried therewith, and as is apparent from Figure 7 the rack frame 33 will roll around the gears 30 while maintaining uniform cooperation between the cam track 41 and the rollers 52, thereby assuring accuracy of any predetermined amplitude of oscillation of the ram. In all-relativeV positions of the cradle frame 32 and rack frame 33, the rack bars 34- and 35 extend at right angles to the top and bottom` sides of the cradle frame 32. During rotation of the cradle frame 32, and While the rack frame 33 is rolling around the peripheries of the gears 30, the sam-e shifts or reciprocates transversely Within the cradle frame 32 and While the rack bars 34 and 35 remain at right angles to the top and bottom sides of the cradle frame.

lt is, of course, to be understood that the rack frame 33- together with the cradle frame 32, Which are shown in normal position, or Wholly within the xed frame 23 in Figures 4, and 6, will in operation of the machine,

move from such position alternately toward opposite sides of the xed frame Iand partially externally of same as is indicated in dotted lines in Figure 7.

Having set forth the invention in accordance with a preferred structural embodiment thereof, what is claimed and desired to be secured by U.S. Letters Patent is:

l. A helical groove cutting machine comprising a work support, support frame means extending above the work support, a tubular guide carried by the support frame means above the work support, a tool bit carrying ram journaled within the tubular guide for simultaneous reciprocation and rotation, an' outer box frame iixedly secured to the top of the tubular guide and having top and bottom aligned openings rotatably and slidably receiving said ram, a pair of aligned gears rigidly secured to the top and bottom of said outer box frame and having aligned bores receiving said ram rotatably and slidably, a box-like cradle frame disposed rotatably within the outer box frame and having top and bottom aligned openings slidably and rotatably lreceiving said ram and turnable relative to said gears,` a rack frame disposed within said cradle frame and movable horizontally relative thereto and including top and bottom horizontal toothed rack bars having meshed engagement with said gears and revolvable about the peripheries of said gears with the .rack frame, guide roller means on the top and bottom of the cradle frame' engaging the backs of said rack bars to maintain them in meshed engagement with said gears, a crosshead rigidly secured to said ram intermediate said gears and Within the cradle frame and inwardly of the rack frame and adapted to' turn with the ram and to reciprocate therewith, a vertical linear track carried by one side of the cradle frame and having guiding engagement with one end of said crosshead, yan angularly adjustable inclined linear cam track carried by the inner side of the' rack frame intermediate said rack bars and having guiding engagement with the other end of said cros'shead, andV eccentric means connected with said ram above the top of said outer box frame for reciprocating the ram axially, reciprocation of the ram with said crosshead simultaneously causing rotation of the ram and spiral movement of the tooly bit through said guided engagement of' one end of the crosshead with said inclined cam track, the cradle frame then-turning within the outer box frame due to the guided engagement lof the other end of the 'crosshead with said vertical track and the rack frame revolving aboutsaid gears and moving slidably upon the cradle frame and maintaining a constant angular relationship thereto. n

2. A helical groove cutting machine yaccording to claim l, and pairs of spaced rollers carried by the opposite ends of the crosshead and'having guided engagement with opposite sides of said vertical and inclined cam tracks.

3. A helical groove cutting machine according to claim l, and reduced hubs on'said gears adjacent the K inner faces of the outer box frame at thel top and bottom thereof and tixedly secured to the outerv box frame, the toothed portions of said gears being spaced from the top and bottom of the outer box frame, and the top and bottom of said rotatable cradle frame being journaled for rotation upon said reducedhubs and between the toothed portions of said gears and the top and bottom of the outer box frame.

4. A helical groove cuttingU machine according to claim l, and wherein said rack bars of the rack frame extend at right angles to the top and bottom of the cradle frame and remain at right angles thereto during all operative positions of the rack frame and cradle frame.

5. A helical groove cutting machine compr1sing work support means, support frame means mounted upon and extending above the 'work support means, an upstanding tubular guide mounted upon the support frame means above the work support means, a rotary reciprocatory ram journaled through said tubular guide and having a tool bit near its lower end to cut helical grooves in the work upon the work support means, an outer frame xedly secured to the top of the tubular guide and being stationary relative to the work support means during the operation of the machine and having opening means rotatably and slidably receiving said ram, a cradle frame mounted for rotation upon a vertical axis inside of said outer frame and having opening means receiving said ram, a pair of vertically spaced gears xedly secured to said outer frame and engaged by said cradle frame rotatably within the outer frame, a rack frame within the cradle frame including vertically spaced rack bars meshing with said gears, said rack frame extending at right angles to said cradle frame and adapted to maintain such angular relationship to the cradle frame while rollng around the peripheries of said gears due to rotation of the cradle frame, the rack frame then shifting transversely through the cradle frame during rotation thereof, means carried by the cradle frame and engaging said rack bars to maintain them in meshed engagement with said gears, a crosshead fixed to said ram between said gears and 'within the cradle frame and inwardly of the rack frame, a vertical track carried by one side of the cradle frame and having guiding engagement with one end of Ithe crosshead, an inclined cam track carried by the inner side of the rack frame and having guided engagement with the other end of the crosshead, and means to reciprocate said ram axially toward and from the work on the work support means.

References Cited in the le of this patent UNITED STATES PATENTS 446,898 Sponsel Feb. 24, 1891 499,683 Smith June 13, 1893v 1,675,136 Sacrey June 26, 1928 2,541,480 Palumbo Feb. 13, 1951 2,771,820 Meyers Nov. 27, 1956 

